Biology is one of the most important subjects for Class 12 students, especially for those preparing for medical entrance exams like NEET. The Biology CBSE class 12 syllabus 2025 26 provides a deep understanding of life processes, genetics, ecology, and biotechnology.

It’s not just about theoretical knowledge, but also about applying concepts through experiments and real-life examples. The syllabus for the 2025–26 academic year has been designed with clarity, balance, and relevance, ensuring students gain both academic and practical exposure. 

CBSE Class 12 Biology Syllabus & Exam Pattern

 Total Marks: 100

• Total Marks for Theory: 70 (3 hours)
• Total Marks for Practical: 30

Theory (70 Marks):

The CBSE Class 12 Biology theory paper is of 70 marks and divided into four sections:

• Section A: Very short answer questions (1 mark each) – 15 marks
• Section B: Short answer questions (2 marks each) – 20 marks
• Section C: Long answer questions (3 marks each) – 15 marks
• Section D: Very long answer questions (5 marks each) – 20 marks
  
  

Unit 6: Reproduction

Chapter 2: Sexual Reproduction in Flowering Plants

• Flower structure; development of male and female gametophytes; pollination - types, agencies and examples; out breeding devices; pollen-pistil interaction; double fertilization; post fertilization events - development of endosperm and embryo, development of seed and formation of fruit; special modes- apomixis, parthenocarpy, polyembryony; Significance of seed dispersal and fruit formation.

Chapter 3: Human Reproduction

• Male and female reproductive systems; microscopic anatomy of testis and ovary; gametogenesis - spermatogenesis and oogenesis; menstrual cycle; fertilisation, embryo development up to blastocyst formation, implantation; pregnancy and placenta formation (elementary idea); parturition (elementary idea); lactation (elementary idea).

Chapter 4: Reproductive Health

• Need for reproductive health and prevention of Sexually Transmitted Diseases (STDs); birth control - need and methods, contraception and medical termination of pregnancy (MTP); amniocentesis; infertility and assisted reproductive technologies - IVF, ZIFT, GIFT (elementary idea for general awareness).

Unit 7:  Genetics and Evolution

Chapter 5: Principles of Inheritance and Variation

• Heredity and variation: Mendelian inheritance; deviations from Mendelism – incomplete dominance, codominance, multiple alleles and inheritance of blood groups, pleiotropy; elementary idea of polygenic inheritance; chromosome theory of inheritance; chromosomes and genes; Sex determination - in humans, birds and honey bee; linkage and crossing over; sex linked inheritance - haemophilia, colour blindness; Mendelian disorders in humans - thalassemia; chromosomal disorders in humans; Down's syndrome, Turner's and Klinefelter's syndromes.

Chapter 6: Molecular Basis of Inheritance

• Search for genetic material and DNA as genetic material; Structure of DNA and RNA; DNA packaging; DNA replication; Central Dogma; transcription, genetic code, translation; gene expression and regulation - lac operon; Genome, Human and rice genome projects; DNA fingerprinting.

Chapter 7: Evolution

• Origin of life; biological evolution and evidences for biological evolution (paleontology, comparative anatomy, embryology and molecular evidences); Darwin's contribution, modern synthetic theory of evolution; mechanism of evolution - variation (mutation and recombination) and natural selection with examples, types of natural selection; Gene flow and genetic drift; Hardy- Weinberg's principle; adaptive radiation; human evolution.

Unit 8: Biology and Human Welfare

Chapter 8: Human Health and Diseases

• Pathogens; parasites causing human diseases (malaria, dengue, chikungunya, filariasis, ascariasis, typhoid, pneumonia, common cold, amoebiasis, ringworm) and their control; Basic concepts of immunology - vaccines; cancer, HIV and AIDS; Adolescent - drug and alcohol abuse.

Chapter 10: Microbes in Human Welfare

• Microbes in food processing, industrial production, sewage treatment, energy generation and microbes as biocontrol agents and bio-fertilizers. Antibiotics; production and judicious use.

Unit 9: Biotechnology and its Applications

Chapter 11: Biotechnology - Principles and Processes

• Genetic Engineering (Recombinant DNA Technology).

Chapter 12: Biotechnology and its Applications

• Application of biotechnology in health and agriculture: Human insulin and vaccine production, stem cell technology, gene therapy; genetically modified organisms - Bt crops; transgenic animals; biosafety issues, biopiracy and patents.

Unit 10: Ecology and Environment

Chapter 13: Organisms and Populations

• Population interactions - mutualism, competition, predation, parasitism; population attributes - growth, birth rate and death rate, age distribution. (Topics excluded: Organism and its Environment, Major Abiotic Factors, Responses to Abiotic Factors, Adaptations)

Chapter 14: Ecosystem

• Ecosystems: Patterns, components; productivity and decomposition; energy flow; pyramids of number, biomass, energy (Topics excluded: Ecological Succession and Nutrient Cycles).

Chapter 15: Biodiversity and its Conservation

• Biodiversity-Concept, patterns, importance; loss of biodiversity; biodiversity conservation; hotspots, endangered organisms, extinction, Red Data Book, Sacred Groves, biosphere reserves, national parks, wildlife sanctuaries, and Ramsar sites.

Practical

• Experiments and Viva: 20 marks
• Record Book and Project Work: 10 marks
• Total: 30 marks

Tips for Preparation for CBSE Class 12 Biology Exam 

These are some practical tips to help you excel in your Biology Exam:

1. Ensure to start by thoroughly going through the latest 12th class Biology syllabus. Focus on high-weightage chapters like Genetics, Biotechnology, Human Health and Diseases, and Reproduction.
   
   
2. You should religiously stick to the NCERT textbook as your primary source. Most of the exam questions are directly picked or framed from NCERT content, so ensure you read it line by line, especially diagrams and examples.
   
   
3. Try to create concise notes for each chapter by yourself, including key definitions, processes, and diagrams. Flowcharts and tables help in quick revisions.
   
   
4. Since Biology is diagram-intensive, you should try to practice important diagrams. Label them accurately as diagram-based questions often carry marks for labelling.
   
   
5. Set a weekly revision schedule for yourself.
   
   
6. Practicing CBSE sample papers and previous year question papers is a must. It helps you get familiar with the question pattern and improves time management.
   
   
7. If you find it difficult to remember complex processes and terms, use memory aids or mnemonics. They make revision faster and more effective.
   
   
8. Maintain a regular study schedule, take breaks, eat healthy, and get enough sleep to keep your mind fresh.
   
   

Mastering the cbse syllabus class 12 Biology syllabus 2025 26 demands a balanced approach of conceptual clarity and practical application. This year’s curriculum aims to equip students with fundamental knowledge essential for board exams and entrance tests such as NEET.

If you diligently follow the syllabus and maintain regular practice, you can achieve high scores and establish a robust foundation in life sciences. Consistency is the key. Hence, studying key concepts, conducting practical experiments, and revising comprehensively will ensure a thorough understanding in both academic assessments and career aspirations in the field of Biology.